Pg Blazer - Online Test Series 19 - Orthopaedics

1. Brown tumors are seen in:

Hyperparathyroidism

Pigmented villonodular synovitis

Osteomalacia

Neurofibromatosis

Brown tumors, also known as osteoclastomas, are a rare manifestation of hyperparathyroidism. They occur due to excessive parathyroid hormone (PTH) production, which leads to increased bone resorption. The excessive bone resorption causes the formation of cyst-like lesions filled with fibrous tissue, blood, and hemosiderin, giving them a brown appearance. These tumors can occur in any bone but are most commonly seen in the spine, pelvis, and long bones. Other conditions listed, such as pigmented villonodular synovitis, osteomalacia, and neurofibromatosis, are not typically associated with the development of brown tumors.

Explanation

Brown tumors, also known as osteoclastomas, are a rare manifestation of hyperparathyroidism. They occur due to excessive parathyroid hormone (PTH) production, which leads to increased bone resorption. The excessive bone resorption causes the formation of cyst-like lesions filled with fibrous tissue, blood, and hemosiderin, giving them a brown appearance. These tumors can occur in any bone but are most commonly seen in the spine, pelvis, and long bones. Other conditions listed, such as pigmented villonodular synovitis, osteomalacia, and neurofibromatosis, are not typically associated with the development of brown tumors.

2. "Rugger Jersey Spine" is seen in:

Fluorosis

Achondroplasia

Renal osteodystrophy

Marfan’s syndrome

Renal osteodystrophy is a condition that affects the bones due to chronic kidney disease. It is characterized by abnormalities in bone mineralization and structure. "Rugger Jersey Spine" refers to a radiographic finding where the vertebral bodies appear dense and have a characteristic striped or banded appearance, resembling the stripes on a rugby jersey. This finding is commonly seen in renal osteodystrophy due to the abnormal deposition of calcium and phosphate in the bones.

Explanation

Renal osteodystrophy is a condition that affects the bones due to chronic kidney disease. It is characterized by abnormalities in bone mineralization and structure. "Rugger Jersey Spine" refers to a radiographic finding where the vertebral bodies appear dense and have a characteristic striped or banded appearance, resembling the stripes on a rugby jersey. This finding is commonly seen in renal osteodystrophy due to the abnormal deposition of calcium and phosphate in the bones.

3. Which of the following malignant tumors is radioresistant?

Ewing’s sarcoma

Retinoblastoma

Osteosarcoma

Neuroblastoma

Osteosarcoma is highly radioresistant

Explanation

Osteosarcoma is highly radioresistant

4. All are true regarding brachial plexus injury, except:

Preganglionic lesions have a better prognosis than postganglionic lesions

Erb’s palsy causes paralysis of the abductors and external rotators of the shoulder

In Klumpke‘s palsy, Horner’s syndrome may be present on the ipsilateral side

Histamine test is useful to differentiate between the preganglionic and postganglionic lesions

Preganglionic lesions have a poor prognosis. They do not recover and cannot be corrected surgically.

Explanation

Preganglionic lesions have a poor prognosis. They do not recover and cannot be corrected surgically.

5. The ideal treatment of bilateral idiopathic clubfoot in a newborn is:

Manipulation by mother

Manipulation and Dennis Brown splint

Manipulation and casts

Surgical release

Manipulation by the mother is the only recommended treatment in a neonate with idiopathic clubfoot. Corrective plaster application / strapping is tried after 4 weeks of age.

Explanation

Manipulation by the mother is the only recommended treatment in a neonate with idiopathic clubfoot. Corrective plaster application / strapping is tried after 4 weeks of age.

6. All the statements are true about exotosis, except

It occurs at the growing end of bone

Growth continues after skeletal maturity

It is covered by cartilaginous cap

Malignant transformation may occur

Growth of an exostosis stops with stoppage of growth at epiphyseal plate. (It is not a true neoplasm)

Explanation

Growth of an exostosis stops with stoppage of growth at epiphyseal plate. (It is not a true neoplasm)

7. A 15 year old boy is injured while playing cricket. X-rays of the leg rule out of a possible fracture. The radiologist reports the boy has an evidence of aggressive bone tumor with both bone destruction and soft tissue mass. The bone biopsy reveals a bone cancer with neural differentiation. Which of the following is the most likely diagnosis?

Chondroblastoma

Ewing‘s sarcoma

Neuroblastoma

Osteosarcoma

Ewings sarcoma has a neural differentiation. Neuroblastoma may present with skeletal metastasis, but is seen in children less than 5 years old.

Explanation

Ewings sarcoma has a neural differentiation. Neuroblastoma may present with skeletal metastasis, but is seen in children less than 5 years old.

8. Which of the following conditions is least likely to present as an eccentric osteolytic lesion:

Aneurysmal bone cyst

Giant cell tumor

Fibrous cortical defect

Simple bone cyst

Simple bone cyst presents as a central lytic lesion.

Explanation

Simple bone cyst presents as a central lytic lesion.

9. All of the following statements are true about development dysplasia (DDH) of the hip, except:

It is more common in females

Oligohydramnios is associated with a higher risk of DDH

The hourglass appearance of the capsule may prevent a successful closed reduction

Twin pregnancy is a known risk factor

DDH of the hip is a condition where the hip joint fails to develop properly. It is more common in females, as stated in the first option. Oligohydramnios, which is a condition characterized by low levels of amniotic fluid, is associated with a higher risk of DDH, as stated in the second option. The hourglass appearance of the capsule may prevent a successful closed reduction, meaning that it can hinder the process of manually reducing the hip joint, as stated in the third option. However, twin pregnancy is not a known risk factor for DDH, making it the exception among the given statements.

Explanation

DDH of the hip is a condition where the hip joint fails to develop properly. It is more common in females, as stated in the first option. Oligohydramnios, which is a condition characterized by low levels of amniotic fluid, is associated with a higher risk of DDH, as stated in the second option. The hourglass appearance of the capsule may prevent a successful closed reduction, meaning that it can hinder the process of manually reducing the hip joint, as stated in the third option. However, twin pregnancy is not a known risk factor for DDH, making it the exception among the given statements.

10. The differential diagnosis of lesion, histologically resembling giant cell tumour in the small bones of the hands or feet, includes all of the following except:

Aneurysmal bone cyst

Fibrosarcoma

Osteosarcoma

Hyperparathyroidism

Histological differential diagnosis of giant cell tumour

Brown tumour of hyperparathyroidism
Non ossifying fibroma
Giant cell reparative granuloma
Benign fibrous histiocytoma
Aneurysmal bone cyst
Osteosarcoma with prominent giant cells
Metastatic carcinoma with giant cells

Explanation

Histological differential diagnosis of giant cell tumour

Brown tumour of hyperparathyroidism
Non ossifying fibroma
Giant cell reparative granuloma
Benign fibrous histiocytoma
Aneurysmal bone cyst
Osteosarcoma with prominent giant cells
Metastatic carcinoma with giant cells